Bead-cobe fob pneumatic tibes



H. K. RAYMOND AND I. R. RNNER.

mo cons FOR PNEUMATIC mes.

APPLICATION FILED JUNE 1 I. 19H.

Patented July 15, 1919.

INVEN Toms, A. M,

A TTORNEY UNITED STATES rafmNT OFFICE.

HARRY G RAYMOND AND IBVIN R. RENNER, OF AKRON, OHIO, ASSIGNORS TO THE B.F. GOOIORICH COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

DEAD-CORE For. PNEUMATIC TIRES.

To all whom it may concern:

Be it known ,thatwe, HARRY Kmo RAY- MOND and IRVIN R, RENNER, citizensof the United States, residing at Akron, in the county of Summit andState of Ohio, have invented certain new and useful Improvements inBead-Cores for Pneumatic Tires, of which the following is aspecification.

This invention relates to the construction of extensible andsemi-extensible beads for pneumatic tires of the clencher type adaptedto be used with either a solid rim or one which is transversely split orone havin a quick-detachable or D. side-rin ur dbject is to provide abead core 0 ample strength which can be manufactured at a lower costthan those heretofore used.

The cores for soft-bead clencher tires, which have to be sufiicientlyextensible to get them over the flanges of a solid rim, have heretoforeusually been made of a plastic compound containing a large proportion ofrubber, usually of the reclaimed or cheaper grades. Such a bead dependsfor its strength principally upon the canvas plies which are wrappedaround the core. In the case of clencher beads for use with rims havingremovable side rings it is desirable to have some degree ofextensibility in order more readily to work the tire casing laterally onand ofi' the rim when the detachable side-ring is removed, and the coresof such beads are frequently made of relatively small rubberized fibrousthreads, either wound circumferentially around and around in a mold tomake an endless core, or in the form of strips of woven fabric torn froma sheet of frictioned fabric, molded, cut to length and spliced. In thelatter case, the cross threads perform no useful function, and in eithercase, the bead core contains more rubber than is necessary, both methodsof making the beads being relatively expensive.

According to our present invention, we make the beads of relativelylarge cabled cords each composed of a plurality of smaller cords orthreads formed of twisted yarn such as cotton yarn. The cabled cords aresuitably coated with rubber, as by running them through a bath ofcement, are collected in a bundle and cured in molds, the result 2 P teing out up into the necessary 1 Specification of Letters Patent.

Patented July 15, 1919.

Application flledJune 11, 1917. Serial No. 174,062.

hs whose. ends are spliced together to ethe annular core. When used for,a soft-bead clencher tire, the bundle of rubberized cabled cords istwisted before being molded,

Of the accompanying drawings,

Figure 1 is a cross section showing part of a tire casing having a beadconstructed accordin to our invention.

Fig. 2 1s a perspective sectional View showmg a fragment of the beadcore made of cords twisted together for a soft-bead tire.

Fig. 3 is a similar view with the cords laid straight for a bead adaptedto be used on rims having detachable side rings, this view showing alsoa portion of the fabric cover.

Fig. 4 is a similar view of the bundle of cords before being molded.

Fig. 5 is h similar view showing one of the cords enlar ed.

In the drawings, 10 represents the bead core as a whole, 11, 11 are thecabled cords composing the same, and 12 is the rubber which coats thesaid cords and connects them together. This rubber is preferably appliedin the form of cement by running the cords separately through a bath ofrubber solution, and as the cords are relatively large in cross section,the amount of rubber present is reduced and there is very littleimpregnation of the cords. Each cord 11, as shown in detail in Fig. 5,is composed of a number of smaller cords 13, in this case six outer andone central cord twisted together into a cable, and each of the smallercords in turn is composed of a number, for example three, strands 14 oftwisted fibrous yarn, such as cotton yarn. Ample strength can be securedwith a relatively-cheap, short staple yarn owing to the fact that anumber of smaller cords of this yarn is cabled together into a largecord.

On emerging from the cement bath, the cords 11 are progressively broughttogether into a circular bundle, as shown in Fig. 4, and the article isthen vulcanized in the usual lbead mold to cure the rubber and impartthe cross-sectional form shown in Figs. 1, 2 and 3. In the case of asoft-bead core for a tire to be used on a solid clencher rim, the bundleof cords before being molded is len twisted s0 tha-tthe core will havethe 00nstruction shown in Fig. 2, which im arts an added d6 0fStretchability. 1 I a semi-extensib e clencher head, the cords 11 areleft straight, as indicatedin Fig. 3. This view shows the usual fabricbead cover 15,

We claim:

1. A pneumatic tire casing having a dumber-shaped head whose core 20prises a series 0f parallel cords each consisting of smaller cordscabled together, each 01- said smaller cords includin a number ofintertwisted attends elf fi rous yam, tegether with vulcanized rubberconnecting the larger cords and of relatively-small volume comare withthat of said cords, the whole 61m ng an extensible bead.

2. A pneumatic tire casing having a clencher-shaped bead whose werecomprises an intertwisted series of parallel cords, eaeh composed ofsmallercords which in turn are composed 0f fibreus yarn, together withvulcanized rubber in relatively-smell volume (:enneeting the largercords, the Whole formin an extensible head.

in testimeny whereof We have hereunto set our hands this 9th day ofJune, 1917.

HARRY KING RAYMOND. IRVIN R. RENNER. I

cum 0! thin patent may N obtained hr in cents eeuh, by addressing theCommissiflner 0f I'atents, Wduhiugton, 1h 0,"

